Suppression of boron penetration in P⁺-poly-Si gate metal-oxide-semiconductor transistor using nitrogen implantation

The mechanism and the optimization of nitrogen implantation for suppression the boron penetration in p⁺- poly-Si gate metal-oxide-semiconductor capacitor is reported. This nitrogen co-implantation process exhibits a good suppression of boron penetration and a better electrical characteristic than that of control sample. It was found that nitrogen combines with the boron to form a B-X complex, retarding the penetration of boron itself, was identified by XPS measurements. The optimum nitrogen dosage is also found in this study.